Semiconductor pressure sensors for measuring a pressure of a fluid such as water or air under moderate temperatures and/or pressures are well known in the art, for example from GB1547592A published in 1979. Typically such sensors comprise a substrate with a thinned portion (called “membrane” or “diaphragm”) upon which membrane a pressure sensitive circuit is arranged, for example a Wheatstone-bridge comprising four piezo-resistive elements. Such a substrate typically further comprises four bondpads in electrical contact with nodes of the pressure sensitive circuit, for example two nodes for biasing the circuit with a voltage or current, and two output nodes for sensing a voltage indicative of the mechanical pressure exerted on the membrane by the fluid. Pressure sensors of this kind are well known in the art, and hence need not be further described here.
Although the basic principles of semiconductor pressure sensors have remained largely the same since 1979, there is continuous ongoing development in several directions, for example to add additional functionality on the same die, such as mechanisms for compensating offset and/or digital read-out circuitry, or to make the pressure sensors suitable for harsh media.
The present invention is related to a pressure sensor assembly suitable for measuring a pressure of fluids which may contain corrosive components, such as exhaust gas, wherein the assembly is of the type that comprises a separate pressure sensor and a separate processing circuit electrically connected to said pressure sensor. Existing solutions are for example described in U.S. Pat. No. 9,200,974(B2) and U.S. Pat. No. 7,992,441(B2) and US20090218643(A1). There is always room for improvements or alternatives.